Enclosure assembly for a disk with a locational and retention cast docket structure for a connector and flexible cable connected to an electronics card

ABSTRACT

A data storage disk drive is provided with a spindle which supports at least one disk having at least one magnetic disk surface to form a spindle assembly for rotation of the disk surfaces about a common axis and a rotary actuator which supports at least one magnetic tranducers for movement about respective disk surfaces. The enclosure includes a base casting and a cover casting. The base casting include predetermined registration surfaces for mounting the spindle and the rotary actuator and having a mating face. The cover casting has a mating face for engaging the base mating face to define the disk drive enclosure for enclosing the spindle, the at least one disk surface, the at least one magnetic transducer and the actuator. The mating faces extend along the length of the disk drive enclosure. The base casting including a locational and retention cast pocket structure for locating and retaining electrical connector and a flexible cable used for connecting to a planar electronics card located outside the drive enclosure.

This is a continuing application of application Ser. No. 08/445,926,filed May 22, 1995 which is a continuation of application Ser. No.08/025,639, filed Mar. 2, 1993, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a direct access storage device (DASD)and, more particularly, to improved electrical and mechanical structuresand arrangements and enclosure assembly for a high performance smallform-factor disk drive.

2. Description of the Prior Art

Computers often include auxiliary memory storage units having media onwhich data can be written and from which data can be read for later use.Disk drives incorporating stacked, commonly rotated rigid magnetic disksare used for storage of data in magnetic form on the disk surfaces. Datais recorded in radially spaced data information tracks arrayed on thesurfaces of the disks. Transducer heads driven in a path toward and awayfrom the drive axis write data to the disks and read data from thedisks.

Disk drive dimensions are normally limited by a form factor, an industrystandard of length, width and height dimensions. As disk drive deviceform factors become increasingly smaller, electrical connections to theusing system can utilize an increasingly greater portion of the deviceform factor. In addition, the device interface and power connectorsused, and the placement of these connectors within the device formfactor results in industry standard elements. The resulting rigidindustry standards provide significant geometric constraints on futuremodels of a given product family or set.

Historically in small DASD's, 51/4" and smaller, a disk drive enclosurefor a head/disk assembly (HDA) is fitted into a metal frame commonlycalled a user frame. This user frame is typically an aluminum diecasting or formed from a sheet metal stamping. Generally, an HDA isattached to the user frame via three or four resilient vibrationisolators or shock mounts. For these isolators to be effective, space isrequired between the HDA and the user frame to allow the HDA to movefreely in response to external vibration or shocks. Threaded holes areprovided at standard locations in the right and left sides and thebottom of the user frame for attaching the disk drive assembly to theusing system box. Therefore, the user frame becomes firmly mounted tothe using system box, but the HDA is both electrically and mechanicallyisolated via the vibration/shock isolators. When magneto-resistive (MR)heads are used within a file, electrical isolation is required betweenthe HDA and the user frame. With smaller form factor disk drives, spaceconstraints also restrict the use of resilient vibration isolators orshock mounts.

Other basic problems in a small form factor disk drive include space forelectronics and the cost. When magneto-resistive (MR) heads are usedwithin a file, a very low amplitude signal is provided so thatamplification is required as early as possible in the electrical path toprevent picking up unwanted noise or causing signal degradation. Therequired amplifier circuits in the data channel, implemented by anintegrated circuit, require external capacitors for tuning and noisefiltering. With a small form factor, the surface area on the actuatoravailable for supporting required arm electronics is limited. In knownarrangements, components are mounted on a flex cable father away fromthe actuator. This conventional arrangement would adversely impactperformance with the MR heads. Other known arrangements use expensivemulti-layer ceramic or flex packaging to allow buried lines and vias. Aneed exists for a cost-effective, efficient and reliable packagingarrangement for arm electronics.

When magneto-resistive (MR) heads are used within a file, transducersand disks must be held at the same electrical potential. Known smallform factor disk drives have provided a conductive path from the flexcircuit to an actuator comb through a mounting screw. A need exists toprovide a low cost manufacturable electrical path from the flex circuitto the comb.

Typically, electrical connectors have been registered in place bypotting or gluing them into holes of the base casting plates. Theseapproaches require a slow labor-intensive process in a clean roomassembly to secure and seal the opening around the connector or requirean additional connector on the inside of the disk enclosure. Often adata cable exits the disk enclosure to transmit read/write head signalsto a card assembly on the outside of the disk enclosure. Typically thedata cable extends along a smooth surface of the base and is squeezedbetween the surface and a rubber gasket. Extending from the deviceenclosure is a dangling data cable that is a source of damage duringassembly and that does not lend itself well to automated assembly.

The spindle motor assembly is driven by signals from a card assembly onthe outside of the disk enclosure. Typically a flex cable is used tocarry signals to the spindle motor. This assembly process also isdifficult to automate and susceptible to damage during assembly.

A mechanically stable enclosure structure is required for the diskdrive. Mounting surfaces for spindle shafts, actuator shafts andactuator pole-pieces have normally been generated by a machining processfor the disk enclosure (DE). The machining process is time consuming andexpensive.

Magnetic disk drive assemblies require make-up air to compensate forsmall, slow leaks in the enclosure, and to adjust to environmentaltemperature and pressure changes. The components inside the drive arevery sensitive to contaminants that can be easily introduced by anincoming air stream. These contaminants include small particles, organicvapors and inorganic gases containing ionic acids. All of thesecomponents may be present in the surrounding ambient air from which themake-up air is drawn.

Traditional filters have concentrated primarily on capturingparticulates from the incoming make-up air. However, more recent designshave incorporated elements to remove the other components. The additionof filter elements for organics and inorganics requires additional spacewhich becomes increasingly difficult to find as disk drive enclosuresbecome smaller. The filter functions become separated into severalstages, which are combined together either on top of, or alongside, oneanother.

Disk drive designs often incorporate a breather port to relieve pressuredifferentials and provide a controlled source of make-up air in theevent of leakage. Breather filters provide filtration for particulatesand, increasingly, for environmental chemicals such as plasticizers andcorrodents. These filters commonly contain a high efficiency particulateair (HEPA) filter medium to remove particles from the air passing intothe drive through the breather. A typical target efficiency for thismedia is 99.97% of particle ≧0.3 micron. A breather filter is designedto be the preferred point of entry of air into the drive and thus musthave a low pressure drop; a typical specification is 0.1 in. of water at30 cc/min. The relatively high pressure drop of HEPA media requires thata relatively large area be employed. The diameter for the media disk forsmall drive breather filters is commonly 10-25 mm. HEPA media used insuch filters are either micro-fiber glass or expanded PTFE. Typicalthickness of these is ≦0.5 mm. For chemical cleansing of the airentering the file, a layer of permeable chemically active media isplaced in the breather directly upstream of the HEPA medium.

One known breather filter design disclosed in U.S. Pat. No. 5,030,260has shown that the airflow path through the filter has a verysignificant impact on the performance and capacity of the elements whichremove organics and acids. In that design, the geometry required toimpart the proper airflow through the filter positioned the upstream anddownstream diffusion paths alongside the filter chamber. This addedgreatly to the overall size of the filter. It also required a relativelylarge flat area for mounting.

SUMMARY OF THE INVENTION

It is a principal object of the present invention to provide a highperformance disk drive that overcomes many of the disadvantages of priorart arrangements. Other important objects of the invention are toprovide a disk drive enclosure incorporating structure for locating andretaining electrical connectors used for connecting to a planarelectronics card located outside the drive enclosure; to provide a diskdrive including a unitary member for containing and positioning a datacable relative to a base enclosure and for sealing an interface betweena data cable connector and a cover enclosure; to provide a disk driveincluding a connector retainer for retaining and securing a powerconnector to a base enclosure; and to provide such a disk drivesubstantially without negative effects.

In brief, the objects and advantages of the present invention areachieved by a data storage disk drive having a spindle which supports atleast one disk having at least one magnetic disk surface to form aspindle assembly for rotation of the disk surfaces about a common axisand a rotary actuator which supports at least one magnetic transducerfor movement about respective disk surfaces. The enclosure includes abase casting and a cover casting. The base casting includespredetermined registration surfaces for mounting the spindle and therotary actuator and having a mating face. The cover casting has a matingface for engaging the base mating face to define the disk driveenclosure for enclosing the spindle, the at least one disk surface, theat least one magnetic transducer and the actuator. The mating facesextend along the length of the disk drive enclosure. The base castingincluding a locational and retention cast pocket structure for locatingand retaining electrical connector and a flexible cable used forconnecting to a planar electronics card located outside the driveenclosure.

BRIEF DESCRIPTION OF THE DRAWING

The present invention, together with the above and other objects andadvantages, can best be understood from the following detaileddescription of the embodiment of the invention illustrated in thedrawing, wherein:

FIG. 1 is an exploded perspective view of a high performance disk driveof the invention;

FIG. 2 is an exploded perspective view of a base casting and apole-piece magnet assembly of the disk drive of FIG. 1;

FIG. 3 is an exploded perspective view of a cover subassembly and filterarrangement of the disk drive of FIG. 1;

FIG. 4 is a side view of the cover subassembly of the disk drive of FIG.1;

FIG. 5 is a fragmentary sectional view taken along the line 5--5 of FIG.4;

FIG. 6 is a bottom perspective view of the disk drive of FIG. 1;

FIG. 7 is an enlarged exploded perspective view of a spindle motorconnector retainer assembly of the high performance disk drive of FIG.1;

FIG. 8 is an exploded perspective view of the spindle motor connectorretainer assembly together with a card assembly of the high performancedisk drive of FIG. 1;

FIG. 9 is a fragmentary sectional view illustrating a spindle motorconnector retainer assembly mounted in a pocket cast into a base of thehigh performance disk drive of FIG. 1;

FIG. 10 is a perspective view of a preferred data cable guide and sealassembly of the high performance disk drive of FIG. 1;

FIG. 11 is an exploded perspective view of a triple fold dynamic flexcable for mounting arm electronics of the high performance disk drive ofFIG. 1;

FIG. 12 is a fragmentary side view illustrating the triple fold dynamicflex cable with an actuator assembly of the high performance disk driveof FIG. 1;

FIG. 13 is a fragmentary exploded perspective view illustrating avoltage reference tab removed from and assembled with the actuatorassembly of the high performance disk drive of FIG. 1;

FIG. 14 is a sectional view illustrating an alternative tube breatherfilter;

FIGS. 15 and 16 are top and bottom plan views, respectively,illustrating diffusion paths of the breather filter of FIG. 14;

FIG. 17 is an enlarged fragmentary top view of a cover illustrating atubular breather filter in dotted line and cast diffusion channels witharrows indicating airflow path of the high performance disk drive ofFIG. 1;

FIG. 18 is a top plan view of a twirler tool;

FIG. 19 is a side view of the twirler tool of FIG. 18;

FIG. 20 is a top view of twirler template used with the twirler tool ofFIGS. 18 and 19 for preparing a twirlpak getter for a breather filter;

FIG. 21 is a side view of the twirler template of FIG. 20 with internaldetails shown in dotted line;

FIG. 22 is an end view of the twirler template of FIG. 20 with internaldetails shown in dotted line;

FIG. 23 is a sectional view of an alternative tube breather filterarranged in accordance with the invention; and

FIG. 24 is a sectional view taken along the line 24--24 of thealternative tube breather filter of FIG. 23.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1 of the drawing, there is shown an explodedperspective view of a high performance disk drive unit designated as awhole by the reference character 10 and constructed in accordance withprinciples of the present invention. Disk drive 10 includes an enclosurestructure 12 produced by two mating aluminum die castings 14 and 16which meet along the length of the device form factor. These arereferred to as a base casting 14 and a cover casting 16, respectively.

Base casting 14 houses all functional elements of the device enclosure12, including a spindle/motor assembly 18 and the actuator assembly 20.In addition, an outer diameter (OD) crash-stop 22, an inner diameter(ID) crash-stop/homelatch 24, and a recirculation filter 28 residewithin the base casting 14. Recirculation filter 28 is received withinbase casting opening 29 for filtering the enclosed air volume with thedisk drive 10. The physical design is such that the actuator assembly 20or spindle/motor assembly 18 may be installed or removed from theenclosure independently of one another and in any preferred sequence forassembly or rework purposes.

It should be noted that disk drive 10 is arranged so that the need forutilizing the entire form-factor length for the structural enclosure 12for the product is eliminated. Disk drive 10 involves reducing thecenterline distance between the disk spindle and the rotational axis ofthe actuator system, reducing the diameter of the bearing systememployed for the actuator, and changing the skew-angle/gap radius of theactuator system to allow full utilization of the disk surfaces.

Referring also to FIG. 2, unique features associated with the basecasting 14 include zero-draft regions providing very preciseregistration surfaces, generally designated as 30, 32, 34, 36, 38 and40, generated in the die-casting process. Each end of a spindle motorshaft, generally designated as 42, is received by the registrationsurfaces 30, 32 and secured to the base 14. Registration surfaces 34 and36 mount an actuator bearing cartridge shaft 44. Registration surfaces38 and 40 provide mounting pads for an upper VCM pole-piece magnetassembly 46 and a lower VCM pole-piece magnet assembly 48, respectively.The upper VCM pole-piece magnet assembly 46 is secured to the basecasting 14 by an adhesive. The lower VCM pole-piece magnet assembly 48is attached to the base by a series of bolts 50.

This unique feature of the invention eliminates the need to produce theregistration surfaces through the process of machining and subsequentdeburring activities, as has been the practice on all known prior diskdrive products of this type. Use of the die-casting process to generatethe registration surfaces 30, 32, 34, 36, 38 and 40 reduces the cost ofmachining.

Base casting 14 is configured as one half of the enclosure structure 12for housing all functional elements of the device 10 to provide thegreatest possible dimensional stability for the critical operationalparameters, since the number of joints subject to displacement anddistortion are minimized. This also ensures the best possibleperformance under changing thermal and vibrational conditions of thedevice 10.

Referring also to FIGS. 3-5 and 17, unique features of the cover casting16 include a perforated rib structure generally designated 52 formedabove high-power electrical modules to facilitate air-flow andconvective heat transfer to the airstream. A cast or machined cavity 54serves as an integral housing for a breather filter 56 illustrated anddescribed with respect to FIGS. 14-17 and an alternative arrangementwith respect to FIGS. 18-24. The cast or machined cavity 54 eliminatesthe need for a separate conventional breather filter housing, such assome form of plastic casing, thereby eliminating unnecessary productexpense. Breather filter media 56 can be stuffed into cavity 54 in thecover casting 16 without need to fasten or bond any additional housedelements into place.

An integral diffusion path 58 is cast in the cover casting 16 forcontrolling the flow of air, indicated by arrows 52A, into thebreather-filter 56. An integral channel 60 of controlled cross-sectionalarea is also incorporated into the die-casting of the cover casting 16to regulate and direct the airstream, indicated by arrows 52B, from thebreather-filter 56 to a low-pressure region indicated generally by 62(FIG. 3) near the center of the rotating spindle system 18. A film 64covering channels 58 and 60 includes an air inlet hole 66 aligned withan inlet to channel 58. By incorporating the integral diffusion path 58in the cast geometry, the need to produce those features in a separatecomponent secured to the device is eliminated. The configuration ofchannel 60 ensures that the point of lowest pressure of the file 10 isemployed to draw air through the breather filter 56 which provides theneeded particulate and chemical treatment of the airstream for all airdrawn into the device, and greatly reduces the potential for air to bedrawn into the disk drive 10 through any alternate path of fenestration.

Referring now to FIGS. 1, 6 and 8, base casting 14 provides a locationaland retention structure generally designated 72 for an electricalconnector 74 connected to a spindle motor 76 via a flex cable 78. Covercasting 16 provides a locational and retention structure generallydesignated by 82 for an electrical data or actuator flex cable connector84 for multiple read/write transducers or heads 86 via a flex cable 88.These functions greatly simplify the manufacturing process of installingor removing from the device 10 a set of electronics carried by a planarcard 90 (FIG. 1), since it is not necessary for the assembler to graspor otherwise handle electrical connectors during the process. Havingreference to FIG. 8, a portion of the electronics card 90 is shown withthe base casting 14. To install the electronics card 90, the card 90 isaligned with the assistance of guide features 92 incorporated in thecard 90 and then the card 90 is pushed down into position, withnecessary electrical connections made to the motor connector 74 housedin the base casting 14 via terminal pins 94. Necessary electricalconnections similarly are made to the actuator flex cable connector 84housed in the cover casting 16. The electronic card is secured in placeto the base 14 with a set of screws (not shown) received through alignedapertures 96 and 98 in the card 90 and base 14.

The base casting 14 and the cover casting 16 are contoured to provide alocalized well generally designated 100 by corresponding regions 102 and104. Localized well 100 accommodates additional height requirementsassociated with the spindle motor assembly 18. As best seen in FIGS. 1and 6-8, the spindle motor 76 includes a flange 106 for supporting astack 108 of disks 110 and a lower portion 112 below the flange 106extending within the localized well 100. The localized well 100, definedby regions 102 and 104, is located and minimized in size to minimize theareal reduction available to the planar electronics card 90, and alsoprovides a ribbed stiffening effect in the region of the spindle system18, which further enhances the dimensional stability of this criticalregion. An aperture 114 is provided in the card 90 corresponding to thelocalized well 100.

Localized well 100 has a bell geometry to facilitate sealing of the diskenclosure 12 which is further provided by a copper-film tape 116encircling the disk enclosure 12 around the length of the enclosure atthe mating line between the two castings 14 and 16 as shown in FIG. 6.The two mating castings 14 and 16 are registered and secured together bytwo fasteners (not shown) received through corresponding apertures 118and 120 in the base and cover castings 14 and 16. The fastener receivingapertures 118 and 120 are located at each end of the enclosure length todraw the halves together against a set of three matching pads generallydesignated 122. The three-point system 122 minimizes distortion effectsimposed on the mating halves 14 and 16 when the fasteners are tightened,which could create assembly stresses in the assembly. Assembly stressescan contribute to performance degradation during file operations andoften lead to production yield problems and customer quality problems.

Both castings 14 and 16 incorporate localized contouring to accommodategeometric spacing requirements for the mating electronics board 90 toprovide optimal use of the device spatial envelope for functionalcomponents of the disk drive 10 both internally and externally to thedisk enclosure 12.

Both castings 14 and 16 are configured as five-sided elements, with theopen face representing the mating surface between the two halves. Thisconfiguration results in a greater structural stability and integritythan is associated with place, tube or box designs due to thereinforcing nature of the five-sided box design and the lack of jointsbetween the mounting/registration surfaces to which critical functionalassemblies 18 and 20 of the device are secured.

Referring to FIGS. 1, 3, 6 and 8, a unique electrical isolation systemis achieved for the two castings 14 and 16 using a series of tenidentical inserts 124 and a pair of insulating members or insulators126. Inserts 124 are simply pressed into a series of correspondingcavities 128 formed of the castings 14 and 16. Inserts 124 are formed ofan engineering plastic material, such as Ultem. Disk drive 10 is notshock-mounted which is achievable by the rotary actuator system 20nominally produced with a static balance about the axis of rotation.Disk drive 10 is desensitized to externally applied inputs which wouldotherwise result in relative motion between the read/write gap of themagnetic recording heads 86 and data tracks which are created on thedisk surfaces 130.

Referring to FIGS. 7-9, a connector retainer generally designated as132, formed of electrically insulative material such as nylon, holds andsecures the spindle motor connector 74 and flex cable 78 to the basecasting 14 and locates the motor connector 74 to the card assembly 90.Connector retainer 132 is a one-piece box including a hinged lid portiondesignated 134 initially located as shown in FIG. 7. After the motorconnector 74 and flex cable 78 are inserted into the retainer 132, thehinged lid 134 is swung over the connector 74 where a snap 136 on thelid fits into a slot 138 to retain the connector. When the spindle motorassembly 18 is attached to the base casting 14, the retainer 132 holdingthe connector 74 and flex cable 78 is slidingly inserted into the pocket72 cast into the base 14. Retaining features or snaps 140 on both endsof the retainer 132 fit into recesses 142 in the pocket walls, securingthe retainer. The card assembly 90 can be attached by slidingly engaginga locating post 144 of the retainer 132 into an aperture 146 the card90, aligning the card pins 94 to the motor connector 74 and creating apositive connection. With this process manual plugging and unplugging ofthe motor connector 74 to the card assembly 90 is eliminated.

Referring to FIGS. 1, 3, 6 and 10, there is shown a data cable guide andseal bracket generally designated 150 arranged in accordance with theinvention. Data cable guide and seal bracket 150 is a formed nylon blockthat contains and positions the flex cable 88 and data connector 84 ontothe base casting. Bracket 150 is a one-piece folding part that locatesthe data cable 88 in relationship to the card connector 84. Bracket 150includes a positioning rail 152 received within a pair of slots 154formed in the base casting 14, as shown in FIG. 2. Bracket 150 includesa forwardly extending portion 156 that extends through an aperture 158within a seal 160 and corresponding aligned hole 161 in the covercasting 16, shown in dotted line in FIG. 3, and provides a sealingsurface with the cover casting 16. Bracket portion 156 defines a pair ofpositioning rails 162 received within a pair of guide slots 164 (oneshown) formed in the cast cover 16. When the actuator assembly 18 isassembled into the base casting 14, the bracket 150 is secured to thebase casting 14 via the cast slot 154 so that the cover casting 16 canbe assembled directly to the base with the bracket 150 positioningitself into the cover casting 16. When the cover casting 16 is assembledwith the base casting 14 as shown in FIG. 6, the flex cable 88 andconnector 84 are held in a position with the connector 84 presented tothe card 90. The seal edge, feedthrough hole 161 and guide slots 164 aredie-cast features of the cover casting 16 provided by the die-castingprocess without adding any additional operations or cost. It should benoted that bracket 150 eliminates the dangling flex of disk driveconventional arrangements.

Referring to FIGS. 11 and 12, there is shown a support arrangementgenerally designated 170 for supporting an arm electronics (AE)generally designated 171. Additional surface area for mountingcomponents of the AE 171 is provided on the actuator assembly 20 byfolding the flex cable 88 to form an S-shape generally designated 172 asshown in FIG. 12 and using a molded wafer 174 to provide a series ofcavities 176 for receiving a plurality of capacitors 180 and providing aflat surface 182 of the flex S-shaped support 170 to mount to theactuator 20.

A top surface 184 of the flex S-shaped support 170 is used to mount themost critical components including two integrated circuit devices 186using direct chip attach (DCA) wirebonding and encapsulation techniques,along with the three most critical noise filter capacitors 188. Theinner layer is used to mount the remaining five capacitors 180. Wafer174, formed of an engineering plastic material such as Ultem, includes apair of upper locating pins 190 and a lower locating pin 192 forpositioning the flex S-shaped support 170 with an actuator comb 194, tosmall tolerances, such as, for example, to +/-0.02 mm. The bottom layerof flex S-shaped support 170 includes a VCM tail 196 that allowsattachment of the VCM coil and the voltage bias reference potential of1.9 volts.

Actuator manufacturing is simplified since no screws are required tohold the flex. The locating pins 190 and 192 allow the use of apressure-sensitive adhesive (PSA) to attach the flex S-shaped support170 to the comb 194. The locating pins 190 and 192 provide the locatingcontrol and prevent the typical PSA creep that can occur underconditions of elevated temperature and continued biasing forces.

The flex S-shaped support 170 provides flex to comb thermal isolation.As the track density increases, track misregistration (TMR) becomesincreasingly critical. The folded package isolates heat from the dataarm electronics (AE) 180, 186 and 188 from the actuator comb 194 andprevents thermal changes from causing actuator arm movement and heatfrom affecting the comb. Power dissipated by the AE module during thewrite mode would cause repeated thermal swings if a direct thermal pathfrom the AE to the comb existed. The flex S-shaped support 170 avoidsthis significant problem.

Referring to FIG. 13, there is shown a voltage reference tab removedfrom and assembled with the actuator assembly 20 of the high performancedisk drive 10. Transducers or read/write heads 86 are magneto-resistive,requiring that the head 86 and the disk 110 be held at the sameelectrical potential. The actuator comb 194 is held to the referencevoltage through the flex AE circuit 171.

Reference tab 200 is a small copper tab plated with a tin-lead alloy andplaced under a bearing attach screw 202. In the actuator assemblyprocess a portion of the flex circuit 171 with an exposed solder pad 204is placed under the tab 200. The tab 200 is bent down onto the solderpad 204 and solder is added to complete the circuit when coil leads 206are soldered.

Reference tab 200 is thin, for example, 0.3 mm and includes a slot 208stamped at the bend location to facilitate the bending operation and toreduce the rate at which heat is conducted from the tip during thesoldering process. Reference tab 200 is symmetric about a mounting hole210 to facilitate the process of placing it under the bearing attachscrew 202.

Referring to FIGS. 14-17, the illustrated filter 56 incorporatesfeatures required for efficient removal of all contaminants in the makeup airstream in a compact shape which can easily be implemented on diskdrives with small form factors below 5.25". The production of the filter56 can be easily automated, leading to lower costs. An electrostaticfilter media which is commercially available from a number of differentsources is used.

In FIG. 14 a cross-section of a possible implementation of the body ofthe filter 56 is shown with a simple tube structure 220 and variouslayers of media stuffed in the tube. Filter housing 54 advantageously isformed within the cover casting 16 as shown in FIG. 17. However, tubestructure 220 also could be a simple molded polycarbonate part, with apartially closed end 222 to support the filter media. In this case, thebottom of the tube contains three small holes 224 that interconnect atthe bottom end of the tube 220 providing the outlet of the filter, forexample as shown in FIG. 16.

The filter is assembled by first placing a scrim 226 at the bottom ofthe tube. Scrim 226 is followed by a piece of electrostatic filter mediagenerally designated 228. The electrostatic filter media 228 iscommercially available from multiple suppliers. Desirablecharacteristics of the electrostatic filter media 228 include a pressuredrop at least one order of magnitude lower than for the high efficiencymembrane medias, that media 228 self-seals inside the tube from packing,and its filtration efficiency is on the same order as the highefficiency membrane medias when used in this application. Next a treatedcarbon element 230 is inserted to satisfy organic and inorganicfiltration requirements. Treated carbon element 230 could be a Kynolfabric treated with sodium carbonate, a treated Kynol felt or yarn, or atreated carbon-loaded polyurethane foam, such as a foam media currentlyproduced by Lewcott Corp. Potassium carbonate treatment could be usedinstead of sodium carbonate to achieve a similar result for the treatedcarbon element 230. An optional piece of electrostatic media 232 couldbe placed at the top of the tube to act as a prefilter.

The tube concept of filter 56 allows for the use of thicker medias in abreather filter assembly. Because of the low pressure drop across thismedia, small diameter filter assemblies are possible. For example, thefilter illustrated in FIG. 14 has a tube OD of 8 mm, a footprint of 0.5square cm and fits in a 15 mm tall disk enclosure. Testing on prototypefilters has confirmed that high efficiency particulate filtration ispossible of greater than 99.995 % efficient at over 100 times the designflow rate. Effective organic and inorganic filtration efficiency andcapacity can be achieved in this small package and at low cost with theproper selection of treated carbon media.

Referring to FIGS. 14-16, the unique flow path for this tube filter 56is depicted. The outlet from the tube is sealed to one wall of the DE 12with a foam seal or foam tape 234. At the outlet of filter 56, thedownstream diffusion path into the file includes a channel 236 formed inthe DE casting 12 and sealed with a mylar or copper tape 238. Thechannel 236 can be ported to an appropriate low pressure region in thedisk drive 10. For example, in the disk drive 10 the breather filter 56is ported close to the center of the spindle assembly 20 as shown inFIG. 1. At the inlet to the filter 56, the inlet diffusion path isformed similarly with a channel 240, sealed with a mylar or copper tape238. Channel 240 is then ported to the outside of the file 10.

The tube breather filter 56 could be used more conventionally byattaching the inlet end to the DE casting. To insure the effectivenessof the chemical media 226, 228, 230, additional flanges (not shown)containing inlet and outlet diffusion paths could be added to the topand bottom of the tube. Breather filter 56 is simple to manufacture. Thepieces of media can be punched and stuffed in the tube 54 or 220 usingautomated processes, and adhesive/ultrasonic welding of the media is notrequired.

Referring to FIGS. 22 and 23, a twirlpak generally designated 250 isshown as getter packing for an alternative long narrow breather filter256. Long narrow filter 256 is one having a ratio of the dimension onthe main axis of flow >2.0 times the smallest dimension perpendicular tothe main axis of flow. Tube filter 56 is an example of a long narrowfilter in which the media is contained in a cylinder which constitutes agas flow channel.

Adjustment of the length and tightness of the twirled media 250 is usedto meet desired filter specifications. Pressure drop of the filter 256is determined by the length of and tightness of the twirlpak 250.Capacity is determined by the quantity of getter in the twirlpak 250.Getter is a medium capable of removing one or more contaminatingsubstances from an airstream. Breakthrough performance is determined byboth the length and tightness of the twirlpak 250.

The twirlpak 250 is prepared by rolling a strip of media around an axiswhich will become the axis of flow in the getter. Unlike conventionalgetter packings such as granular carbon, the amount of media in atwirlpak 250 can be varied by altering the compression achieved in thetwirling operation. An example of the procedure for preparing a longnarrow tube filter 256 using a twirlpak follows.

A device comprised of a twirler 258 illustrated in FIGS. 18 and 19 and atwirling template 260 illustrated in FIGS. 20, 21 and 22 is utilized,which allows the getter media to be twirled and then inserted into thelong narrow tube filter 256 without handling of the twirlpak 250. Firsta strip of getter media, e.g., carbon fabric, is cut so that the widthis equal to the desired depth of getter in the tube filter 256. Next thelength of the strip of getter media is selected to provide the desireddegree of compaction of the media in the tube filter. The length ischosen to give about 75% volume filling of tube cavity. The twirlingtemplate 260 consists of a slot 262 and a cylindrical cavity 264 whichhas a diameter slightly smaller than that of the tube filter 256 shownin FIGS. 23 and 24. The strip of getter media is placed in the slot 262of the twirling template 260. The relative position of the slot and thecylindrical cavity determine if the media is to be twirled in a singleor double spiral. The twirler 258 is comprised of a shaft 266 with adiameter slightly smaller than the cylindrical cavity 264 of thetwirling template 260. In this shaft 266 are mounted a pair of narrowpins 268 aligned parallel with the axis of the shaft 266. The spacing ofthe pins 268 allows them to just slide over the thickness of the gettermedium as seen in FIG. 24. The axis of the twirler 258 and that of thecylindrical cavity 264 in the twirling template 260 are aligned, and thetwirler 258 is inserted far enough into the twirling cavity 264 to allowthe pins 268 to pass along the full width of the getter media strip. Thetwirler 258 is rotated on its axis to twirl the media strip into thetwirlpak 250. The cylindrical cavity 264 of the twirling template 260 isthen aligned with the tube filter 256, so that the axis of both arecommon. The twirlpak 250 is moved from the cylindrical cavity 264 of thetwirling template 260 to the desired position in the tube filter 256.The ram used to move the twirlpak may be the shaft 266 of the twirler258, or another properly-sized cylindrical shaft. If desired, thetwirlpak 250 may be loaded into a cylindrical tool for subsequenttransfer to the tube filter 256 in a separate operation. This may be ofparticular advantage if the twirlpak is to be loaded into a tube filterwhich is integral to a complex device. This might be desired in order toseparate the operations of handling the carbon getter media from thefinal produce which will contain the tube filter.

Filters using the twirlpak, which is prepared and loaded in this mannermet both breakthrough and pressure drop performance criteria.Breakthrough is the ratio of the contaminant concentration exiting agetter or chemical breather filter (CBF) to the contaminantconcentration entering a getter or CBF.

A series of tests were carried out to directly compare the performanceof tube breather filters. The pressure drop of each filter was measuredusing a flow of 30 cc/min of clean dry nitrogen. The pressure drop ofthe tube itself and gas lines were constant and were subtracted. Theseresults are summarized in Table

                  TABLE 1    ______________________________________    Tube Breather Test Results    Tube Breather Getter Height = 6.5 mm Nominal                      Delta P     Meets  Meets    Adsorbant T.sub.0.001 /                      at 30 cc/min                                  projected                                         pressure    Material  T.sub.0.80                      (in H2O)    lifetime                                         criteria    ______________________________________    Act. carbon              0.78    0.055       No     Yes    coated form    Act. carbon              0.59    0.055       No     Yes    granules    Act. Carbon              0.82    0.13        Yes    No    felt    Act. Carbon              ≧0.82*                      0.21        Yes*   No    fabric    Act. carbon              0.80    0.06        Yes    Yes    twirlpak    ______________________________________

As used in Table 1, T₀.001 /T₀.80 is a measure of the effectiveness ofcontact of the airstream with the media. In the case of the foam, thecontact was excellent, resulting in an excellent sharpness or largeratio, but the total capacity and lifetime were very low although theloading of carbon on the foam was reported by the manufacturer to be themaximum achievable. Delta P is the pressure drop across the twoelectrostatic particulate filters plus the adsorbant media. Delta P doesnot include the pressure drop across the diffusion channels. Projectedlifetime is based on both the time to reach the clip level and criteriawhich are file specific. Clip level is the maximum level of breakthroughwhich will give the getter or CBF a desired performance level.Breakthrough was not tested for activated carbon fabric but would beexpected to perform as well or better than activated carbon felt.*Projected data based on other results.

While the invention has been described with reference to details of theillustrated embodiments, these details are not intended to limit thescope of the invention as defined in the appended claims.

We claim:
 1. A magnetic storage disk drive having a spindle whichsupports at least one disk having at least one magnetic disk surface toform a spindle assembly for rotation of said at least one disk surfaceabout an axis and a rotary actuator which supports at least one magnetictransducer for movement about respective disk surfaces comprising:a diskdrive enclosure including a base casting and a cover; said base castinghaving a mating face; said cover having a mating face for engaging saidbase mating face to define said disk drive enclosure for enclosing saidspindle, said at least one disk surface, said at least one magnetictransducer and said actuator; a flexible cable coupled to a motor ofsaid spindle within said disk drive enclosure and extending from theinterior of said disk drive enclosure to the exterior of said disk driveenclosure; an electrical connector coupled to a distal end of theflexible cable; said base casting including a locational and retentioncast pocket structure for locating and retaining said electricalconnector and said flexible cable used for connecting to a planarelectronics card located outside said disk drive enclosure; and aunitary connector retainer provided within said locational and retentioncast pocket structure, said unitary connector retainer adapted todetachably support said electrical connector, a locating post formed onsaid unitary connector retainer, said locating post adapted to locateand engage a corresponding structure of said planar electronics card tofacilitate positioning of said planer electronics card with saidelectrical connector within said unitary connector retainer.
 2. Amagnetic storage disk drive as recited in claim 1 wherein said unitaryconnector retainer receives said electrical connector and said flexiblecable and includes retaining features received within cooperatingrecesses formed in said base casting locational and retention castpocket structure; said electrical connector connected to said spindlemotor via said flexible cable.
 3. A magnetic storage disk drive asrecited in claim 2 wherein said connector retainer is a one-piece boxformed of electrically insulative material and including a hinged lidportion and wherein said locating post further comprises a registrationpost slidingly received within a cooperating aperture in said planarelectronics card for positioning said electrical connector with saidplanar electronics card; said planar electronics card including aplurality of electrical pins for connection with said electricalconnector.
 4. A magnetic storage disk drive as recited in claim 3wherein said cover includes features receiving a unitary bracket.
 5. Amagnetic storage disk drive as recited in claim 4 further includes adata cable and a data connector contained by said unitary bracket.
 6. Amagnetic storage disk drive as recited in claim 5 wherein said unitarybracket includes a unitary member having a forwardly portion extendingthrough a feedthrough opening in said cover for positioning said dataconnector in operative relation to said planar electronics card.
 7. Amagnetic storage disk drive as recited in claim 6 wherein said forwardlyportion defines positioning rails received within a pair of guide slotsformed in the cover.
 8. A magnetic storage disk drive as recited inclaim 6 further includes a seal received within said feedthroughopening.
 9. A magnetic storage disk drive as recited in claim 5 whereinsaid unitary bracket is a one piece folding part.
 10. A magnetic storagedisk drive as recited in claim 5 wherein said unitary bracket is formedof electrically insulative material.